Power saw for cylindrical printing plates



Sept. 16, 1952 a, w, BUNGAY 2,610,389

POWER SAW FOR CYLINDRICAL PRINTING PLATES Filed Nov. 29, 1949 BShoots-Sheet 1 INVENTOR. 650mm M Bu/vG/n A TTORNEYS.

Sept. 16, 1952 5, w, BUNGAY 2,610,389

POWER SAW FOR CYLINDRICAL PRINTING PLATES Filed Nov. 29, 1949 5Sheets-Sheet 2 INVENTOR.

650E615 h! EU/VGAY A TTOfFNEYS Sept. 16, 1952 c. W.BUNGAY POWER SAW FORCYLINDRICAL PRINTING PLATES 5 Sheets-Sheet 3 Filed Nov. 29, 1949INVENTOR. Geo/ea: M Bu/ve/n A TTO/PNEYS.

Sept. 16, 1952 e. w. BUNGAY 2,610,389

POWER SAW FOR CYLINDRICAL PRINTING'PLATES Filed Nov. 29, 1949 5Sheets-Sheet 5 INVENTOR. 65052;: W Bu/vam A TTORNEKS.

Patented Sept. 16, 1952 -"row t; i ro remo e? The present inventionrelates/to a novelfand improved motor driven saw for "sawing -cylindri-:cal printing plates along edgesprior to the finishing -operation.

Objects and advantages of the invention will beset forth in parthereinafter and in part will be obvious herefrcm, or may be learned bypractice with-the invention, the same being realiZed-and attained bymeans-of the instrumentalities and combinations pointed outin theappended claims.

Theinvention consistsin the novel .iparts, constructions, arrangements,combinations and improvements herein shown and described.The-accompanying drawings, referred to'h'erein and constituting a parthereofinillustrate one embodiment of the invention' and together .withthe description, serve to explain the principles of "the invention. Y 'HOf the drawings:

' Figure l .is a side elevationjcf a typical and illustrative embodimentof the present invention;

Figure 2 is a .front elevation lacking from the right of Figure 1; .l ai 1 -Fi'gure 3 is aideta'iled elevationshowing the clutch mechanism andfluid pressure motor :for holding the plate while it is sawed; I

Figure 4 is a detail horizontal section taken on'zthelin'e 4-'- ,4"ofFigure 2; t

:Figure 5 is :a; horizontal section. taken onfth'e line :5-\-.5 ofFigurefl; Y

.Fig'ure 6is1a fragmentary vertical section taken on'the lineE-i-fi ofFigure 5;

V'Eigure lislasectional .view takenton the line 1-1 of Figure 6 showingthe internal structure of the clutch and reversing gears; V igure 8 is asectional viewta-ken on theline 8- 8-of Fi ure'hand, r I

Figure 9 is adetailed elevation showing vthe clutch operating leversinneutral position.

The present invention has for itsobj'ect the provision of a novel, andimproved cylindrical plate'saw for sawing curvedstereotypesandelectrotypes. A further object is the provision .0f.:a' power sawwhich may be rapidly ,operatediwith'a minimum of manual efiort, andproduces accu- I trativelyembodied.intmechanism comprising at theirstraight parallel rately; sawed -plateswith complete certainty. ;A

further object is theprovision of a platejsaw which will operate withequal accuracy'on plates of widely different diameter. Theinvention-further provides-a power saw of;the kind set forth in whichthe plate is supported vertically ona flattable and maybe easily lifted.to and from the saw table. V a

The-power-saw of the present invention is-il-lusflat table onwhich: thecurved plate ;is supported with oneofwits cilrvededges resting ongtheflat surface. A pair of guide rods, close together and parallelxtoeach-other are perpendicular to the table andserve to'accuratelyposition the plate so that the *saw passing-between them ,cutsthe platealong radial straight edgesaccurately per: pendicular to the planeofthe' curvededges; A clamping. memberis power moved along the guiderods so as to olam'p the plate between it and the table. .Thesaw'isrpower driven. by "a "vertically movable motor on guideways' whichcarry a frame supporting. both: the saw and motor. -A leadi'screwis.;a:lso motor driven through-a clutch and reversing gearso'that thesaw and i'ts:motor are lowered andxraiseiby the-elevator'lm'otor. Automatic .means are provided-for controlling the travel of the motoredrivensaw; After one straight edge of the v ;plate has been sawed, the clampis .released,;th'e;plate shifted, again clamped and the secondcutistaken and is, parallelgtothe It :will be understood thatsthe;fioregoing general description: and the following detailed descriptionas well are-exemplary and explanatory of "the finventiongbut are 1 notrestrictive thereof.

jiReferring inowcin {detail .to the illustrative ,e m bodiment of thepresentiinventionrasyshown specifically in the. accompanying drawings,there is provided-a heavy rigidbase 10 one part of which isfinished toprovidea flat horizontaltable l2 adapted tor eceive the curved,'uniplanar edge M ofv a partigcylindrical stereotype, velectrotypeorzother rigid arcuategprinting plate It which is to have its straightparallel edges trimmed to provide radial surfaces by which the plate maybeclamped to -;the cylinder duringprinting. The curved edges M oftheplate 16, as cast orotherwise formed, {are generally trueand form ,thereference surfaces by which the Qtheredgesmay be'trimmed, o

M ans arenrovided for accurately locatingthe plate,;so that the platemay be accuratelyzzpositioned with the saw blade on its radius.

Table I2 is formedwithan edge-slot 18 wide enough to provide clearancefor :a :jcircular'saw blade and deep enough .to receiveizthesawibladefar enough to cut through the-plate. Closely adjacent the sloth-l8.are'two parallel, rods 1120 fixed. in the tablefsurface lief base. [Inand extending upwardly therefrom; The :exteriorrof these cylindricalrods Iform rsurfacesflto' :contact with :the convex surface of theplateilifi ofany normal size, so a radius of the plate l5 :liesmver 3the slot I8 and is uniformly spect to the saw blade.

Means are provided for clamping the plate [6 during the sawingoperation. As embodied, a flat clamping member 22 is movable up and downalong rods 26 at their portions of reduced diameter. Clamp 22 ispreferably power actuated by means of a, reversible fluid pressure motor24 under control of a normally actuated reversing valve 26. Thereversing valve 26 controls the positioned with resupply of fluidpressure from supply pipe 36 to the pipe 3| or 32 connected to the upperand lower ends of the motor cylinder 24 so as to lower or raise(respectively) piston rod 34 which is connected to the cross head 36which'is oppositely slotted at its ends and is engageable in the grooves38 formed along the length of the slidable rods 39 which are connectedto the clamp 22. The clamp 22 is provided with hand grips 46 at its endsand is apertured to slide on the guide rods 20, while the upper ends ofthe rods 39 are slidable in the upper guide plate 42. To insure theproper looking of the cross head 36 in the grooves 38," a leaf spring 44is secured to the cross head and tends to pull the slotted end into thegroove 38. On the other end, a stop 46 is provided to prevent the crosshead being swung too far so as to endanger breakage of the spring 44.

By manually lifting or lowering the clamp 22 while the cross head 36 isswung by handle 31, the clamp may be adjusted so as to be power actuatedfrom plate released to plate securing position for all normal lengths ofplates.

The motor driven saw is carried on a vertically movable frame and thesaw rotates in the same pathas itis bodily moved. As embodied, a slide50 is movable up and down along a dovetail guideway 52, and is gibbedthereto. On one side, the slide is formed with suitable bearings for thesaw shaft 54 on one end of which is mounted a circular saw blade 56,while on the other end there is provided a double pulley 58. A suitablesaw guard 60 is mounted on the slide 50 to cover the saw except wherethe saw passes into slot I8.

A motor 62 drives saw pulley 58through belts 64 and is mounted on aplate 66 supported on the slide'50 by means of the rigid rods 68, themotor being so positioned that the vertically movable saw and motor aresubstantially balanced about the guideway '52 so that any tendencytobind is avoided. A suitable power supply and switch are'provided formotor 62. a e

For moving the motor-saw unit up and down, power means are provided forslowly moving the saw down as it cuts the plate and for more rapidlymoving the saw upwardly on its idle return stroke. As embodied, a motorI0 is mounted on the upper end of the column 12 which supports guideways52. Motor I0 drivesa'bevel pinion 14 through reduction pulleys I6 so' asto drive two compound gears I8 and 80. g

A threaded rod 84 extends vertically parallel to the guideways 52 andengages with a threaded sleeve 86 fast to the slide 50 so that rotationof the rod 84 raises orlowers the slide 50 and the motor 62 and saw 56carried thereby. Rod 84- is journalled at its upper end in bearings 88in the gear box in which the gears I4, I8 and 89 are rotatably mounted.

Reversible clutch means are'provided for driving rod 84 from gear I4 andfor this purpose a dog clutch member 92 is slidably keyed to the rod 84at its upper unthreaded end. Member 92 may be moved upwardly intodriving engagement with the clutch member 94 formed integrally with aedge of the metal plate.

gear journalled for rotation on shaft 84 and meshing with the spur gearportion of compound gear 16. Gear 18 and gear 94 form a speed reducingpair and slowly drive the threaded rod 94 so as to slowly lower the sawas it cuts the Below clutch member 92 and cooperating with the lowerface thereof is another gear 96 so that the rod 84 may be driven fasterin the opposite direction, gear 96 meshing with the spur portion of thecompound gear 88, gears and 96 forming a speed increasing unit wherebythe rod 84 is turned faster and in an opposite direction than by gearsI8 and 94. In the position shown in Figure 7, clutch member 92 is inneutral position and rod 84 is stationary holding the saw againstvertical movement.

For shifting the clutch from neutral to either up or down motion of thesaw, a fork 98 has pins 99 which run in an annular groove in the clutchmember 92. Fork 98 is pivotally mounted on shaft I III] and may be swungby handle IOI so that clutch member 92 engages with either gear 94 or 96or with neither.

Means are provided for holding the clutch in any of its three positionsand for returningthe clutch to neutral position from .either of itsother positions when the saw has reached a definite point in itsvertical travel. For this purpose, a fork I63 is'keyed to shaft I00 andhas flat ends which are engageable with a roller I04 carried by an armI96 spring urged into contact with one of the flat ends of fork I63 orwith the notch between the forked end. Thus the spring and roller I04tend to holdthe clutch in any position until it is pushed manually orotherwise to another position.

Variably positionable stops are provided for engagement with the motorsaw sliding-unit to release the clutch to neutral position as it reachesa predetermined point in its vertical travel. Vertical rod I'III extendsparallel to the guideways 52 being supported at its lower end in a guideplate I I2 and pivoted at its upper end to a bell crank H4 keyed toshaft I00. At its lower end, rod HO has a coil spring H6 compressedbetween collar I I8 and plate I I2.

Rod H8 passes through an eye I20 carried on one of the rods 68. Eye I20is adapted to contact with collar I22 near the bottom of rod I I I] andas the saw moves upwardly with. a movable collar I24. Collar I24 has aradial pin I26 which is spring pressed to engage with one of the holes I28 formed in rod I I0,.while collar I22 has a set screw to hold it inthe desired vertical position.

As soon as eye I20 engages with collar I22 or I24, travel of the saw asdriven by motor 70 causes rod I I6 to be moved thereby swinging the fork98 and the clutch member 9 2 towards neutral position, which movement isassisted in its later stage by the spring pressed roll-er I04.

In operation, clamp 22 is adjusted to the proper height by hand lever 36and after plate I6 has been seated against rods 20 on the faceof tableI2, valve 26 is moved to force the clamp 22 powerfully against the uppercurved edge of the plate thereby securely clampin the plate with sawblade 56 radial with respect to the plate, regardless of its diameter. lMotor 62 and motor III are then energized and clutch lever "II is pushedup to'cause the'saw to travel downwardly until eye I 20 engages stopcollar I22-to stop downward travel of the saw. During its downwardtravel, the saw cuts one straight edge of the curved plate I6. Lever IOIis then pulled down and the saw is rapidly raised until eye I20 engagescollar I24 to restore the clutch to neutral.

Clamp 22 is then released by valve 26, the plate H5 is shifted so thatit is in position for its other straight edge to be sawed and theoperations are repeated for sawing that edge, thereby severing thecylinder into a plurality of curved plates.

The invention in its broader aspects is not limited to the specificmechanisms shown and described but departures may be made therefromwithin the scope of the accompanying claims without departing from theprinciples of the invention and without'sacrificing its chiefadvantages- What is claimed is:

1. Apparatus for mechanically sawing the straight edges of aparti-cylindrical printin plate including in combination a flathorizontal table, a pair of parallel rods rigidly mounted on and normalto the surface of the table, a saw slot in the table surface between therods, a power driven saw, and means guiding the saw in a path parallelto the rods, said parallel rods being engageable with the convex surfaceof the plate to locate the plate on the table in a definite relation tothe path of the saw.

2. An apparatus as claimed in claim 1 in which power means slidable onsaid parallel rods are 6 provided for holding the plate firm against thetable.

3. Apparatus for mechanically sawing the straight edges of aparti-cylindrical printing plate including in combination a fiathorizontal table to receive the plate while standing on a curved edge, apair of parallel rods normal to the table surface, a saw slot in thetable surface between the rods perpendicular to a line through the rods,a power driven saw movable vertically and parallel to the rods, saidrods forming stops engageable with the convex surface of the plate toposition the plate with the saw radial thereto and separate power meansfor moving the saw in either vertical direction.

GEORGE W. BUNGAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,387,869 Royle Aug. 16, 19212,372,818 Dostal Apr. 3, 1945 FOREIGN PATENTS Number Country Date 6,701Great Britain Mar. 18, 1913

